JPH0481758A - Production of photomask and semiconductor device - Google Patents

Abstract

PURPOSE:To facilitate the attachment and detachment of a pellicle frame without using an adhesive by simultaneously pressing the pellicle frame for adhering and fixing at a specified distance provided from the pellicle and a photomask and fixing the frame and the photomask by using attachable and detachable jigs without providing an adhesive layer therebetween. CONSTITUTION:The pellicle frame 12 for adhering and fixing the pellicle apart the specified distance provided therefrom and the photomask 13 are simultaneously pressed and are fixed by using the attachable and detachable jigs without providing the adhesive layer between the frame and the photomask. For example, the jigs for simultaneously holding and fixing this pellicle frame 12 and the photomask 13 is constructed to press the pellicle and the photomask by utilizing the elastic force of the jigs themselves. Since the adhesive is not used for fixing the photomask and the pellicle frame in such a manner, the adhesive does not remain on the photomask at the time of removing the pellicle frame and, therefore, if a substitutive pellicle frame is previously prepd. the immediate use of the photomask is enabled by instantaneously exchanging the pellicle frame. The mass productivity thereof is greatly improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photomask having a pellicle, and more particularly to a method for fixing a pellicle frame to which a pellicle is adhesively fixed to a photomask.

[Prior Art] In the recent microfabrication process of the photoetching process in the manufacture of semiconductor devices, miniaturization of semiconductor devices has been dramatically improved by using a reduction exposure device (hereinafter referred to as a stepper) using a photomask. However, pattern defects due to transfer of foreign matter on the photomask to the resist on the wafer became a problem after the process rule of around 1 μm. Foreign matter on the photomask is directly transferred onto the wafer, so managing the foreign matter is extremely difficult.

FIG. 5 shows a diagram in which a pellicle is attached to a photomask according to the prior art. In recent years, in order to prevent the transfer of foreign matter, a pellicle (53) typically made of nitrocellulose is adhesively fixed to a pellicle frame (52) typically made of aluminum alloy, and the pellicle frame (52) is also coated with a photomask (51). Glue and fix to cover the pattern area. This prevents foreign matter from adhering to the pattern surface on the photomask (51), and even if foreign matter adheres to the pellicle surface (53), it becomes defocused during exposure, making it easy to manage foreign matter. It was relatively easy. However, it is still essential to manage foreign substances on the pellicle surface (53) and the pattern surface of the photomask (51).

When foreign matter is found on the pellicle surface (53), it is removed by spraying nitrogen gas or the like into the membrane onto the foreign matter on the pellicle surface. However, since the nozzle for injecting nitrogen gas is thin, the pellicle (53) is often torn due to operational errors. Also, pellicle (53)
Since it is not very strong, it can be accidentally damaged during daily work. In this case, after removing the pellicle (53), the pellicle frame (52) and photomask (51) are immersed in an organic solvent such as acetone or xylene for several minutes, and then the pellicle frame (52) is removed from the photomask. mask(
51). However, the photomask (5
1) and the pellicle frame (52), there is an adhesive for bonding and fixing the photomask (51) and the pellicle (52), and when the photomask (51) is separated, the photomask (51)
The adhesive will remain on the surface. As a method for removing the adhesive from the photomask (51), the adhesive is further dissolved and removed using an organic solvent such as acetone or xylene.

[Problems to be Solved by the Invention] However, the prior art has the following problems.

The adhesive remaining on the photomask when the pellicle frame and the photomask are separated is removed using an organic solvent, but it is difficult to remove the adhesive completely. Further, the adhesive or the pellicle remaining on the pellicle frame may be dissolved by the organic solvent, and the adhesive or the pellicle may adhere to the photomask. In this case, it is difficult to detect adhesives and pellicles because they have high transmittance. Therefore, even if the adhesive or the pellicle adheres to the mask, the mask may be used without being noticed. Furthermore, after separating the pellicle frame from the photomask and cleaning it,
The photomask cannot be used until the pellicle is attached again, resulting in a significant drop in mass production efficiency.

The present invention solves the above problems, and
The purpose of this is to make it easier to attach and detach the pellicle frame without using adhesive when fixing the pellicle frame to the photomask, and to make it easier to attach and detach the pellicle frame if the pellicle frame needs to be separated from the photomask for some reason. However, since it is easy to attach the pellicle again, the time during which the photomask cannot be used is greatly reduced.

[Means for Solving the Problems] 1) In a photomask equipped with a pellicle, an adhesive layer is not provided between the photomask and a pellicle frame for mounting and fixing the pellicle at a certain distance, and the The pellicle frame and the photomask are simultaneously pressed and fixed using a removable jig.

2) The photomask according to claim 1, wherein at least a portion of the pellicle frame is provided with a holding margin for simultaneously holding and fixing the pellicle frame and the photomask using a jig.

3) The photomask according to claim 1, wherein the jig for simultaneously holding and fixing the pellicle frame and the photomask has a structure that uses its own elastic force to hold the photomask. The photomask according to claim 1, wherein a non-slip surface of the fixing jig that contacts the pellicle frame and the photomask is provided.

5) The photomask according to claim 1, characterized in that a cushioning material is provided on the surface of the pellicle frame that comes into contact with the photomask. 6) The photomask according to claim 1 is used in a photo process for manufacturing a semiconductor device.

[Example] Fig. 1-Person, Fig. 1-B, and Fig. 1-〇 are diagrams showing an embodiment of the present invention.

As in the prior art, a pellicle typically made of nitrocellulose is adhesively fixed to a pellicle frame (12) typically made of aluminum alloy.

The pellicle frame (12) differs from conventional pellicle frames in that the pellicle frame (12) and the photomask (13)
The contact area extends to the interface of the photomask (13) as shown in the figure. The fixing jig (11) is arranged to sandwich the upper and lower pellicle frames (12) and the photomask (13) as shown in FIG. 1-B.

In this example, the pellicle frame (12) and the photomask (
13) is completely fixed. This makes it possible to fix the pellicle frame to the photomask without using an adhesive, which is the greatest feature of the present invention.

Next, the pellicle frame used in this example is shown in FIGS. 2-8 and 2-B. In this figure, the pellicle (22) is
It is adhesively fixed to the pellicle frame (21) with an adhesive. The fixing jig (11) in FIG. 1 is attached to the widening part of the pellicle frame (21) as shown in FIG. 2, to further improve sealing and fixing properties. Furthermore, FIG. 2-B is an upside-down view of FIG. 2-A,
In this figure, the photomask (13) in FIG.
A cushioning material (23) is provided at the portion that comes into contact with the. The pellicle frame (21) and the photomask in Figure 1 (
13) Since the contacting part is not necessarily a perfect plane,
If the photomask (13) is left in this state, there is a possibility that foreign matter or the like may get mixed into the portion of the photomask (13) covered by the pellicle frame (21). The cushioning agent (23) prevents such foreign matter from being mixed in. Furthermore, the cushioning agent (23) also has the effect of preventing the photomask (13) in FIG. 1 from being damaged by the pellicle frame (21).

Next, FIG. 3-A is a schematic diagram of a fixing jig in an embodiment of the present invention. In this embodiment, the fixing jig is made of aluminum alloy, similar to the pellicle frame (21) in FIG.
3) is made of iron and fixed by welding. As a result, the fixing jig (32) is moved to the first position by the elastic force.
Photomask (13) and pellicle frame (12) in the figure
can be fixed. When further fixed, when attached to the pellicle frame (12) in Fig. 1, the fixing jig (
A thin rubber (31) is provided inside the fixture (32) to prevent the fixture (32) from coming off. Thanks to these functions, the fixing jig almost never comes off when fixing the photomask and pellicle frame.

For example, if the pellicle is damaged by using the photomask equipped with the pellicle used in this example,
The pellicle frame (12) can be removed by simply removing the fixing jig (11) in Figure 1, and since no adhesive is used to fix the pellicle frame (12), a substitute pellicle frame can be prepared. If this is done, the photomask can be used again as before by instantly replacing the pellicle frame.

As a result of the above, there is no adhesive remaining on the photomask after removing the pellicle frame when the pellicle is damaged, which was a problem with the conventional technology, and moreover, the fixing jig is removed when removing the pellicle frame. Since the process is completed with just a few simple steps, there is no need to soak the mask in an organic solvent as in the conventional technology, which greatly improves work efficiency. Furthermore, the work required to eliminate adhesive and clean the photomask, which is required in the conventional technology, can be significantly omitted, and the time required to replace the pellicle is minimized in the event that the pellicle is damaged. Unlike photomasks, the photomask does not become unusable for long periods of time, and mass productivity in manufacturing semiconductor devices is significantly improved.

An embodiment of the present invention has been described above, but in addition to this, (1) a handle (34) is provided to facilitate removal of the fixing jig (32) as shown in FIG. 3-B.

(4) When fixing the photomask (43) and the pellicle frame (42) as shown in Fig. 4, they are fixed by sandwiching them between the fixing jigs (41) from four directions.

■ To prevent the fixture from slipping, provide a step where the fixture and pellicle frame meet.

■ Use plastic or iron as the material for the fixing jig.

It goes without saying that the same advantages as the embodiments of the present invention can be obtained also in the above cases.

[Effects of the Invention] 1) In a photomask equipped with a pellicle, an adhesive layer is not provided between the pellicle frame and the photomask for mounting and fixing the pellicle at a certain distance, and the pellicle frame and the The photomask is held down at the same time and fixed using a removable jig.

2) In the photomask according to claim 1, at least a portion of the pellicle frame is provided with a holding margin for simultaneously holding and fixing the pellicle frame and the photomask using a jig.

3) In the photomask according to claim 1, the jig for simultaneously holding and fixing the pellicle frame and the photomask has a structure that uses its own elastic force to hold the jig.

4) In the photomask according to claim 1, a non-slip member is provided on the surface of the fixing jig that contacts the pellicle frame and the photomask.

5) The photomask according to claim 1, characterized in that an adhesive/solution material is provided on the surface of the pellicle frame that is in contact with the photomask. 6) The photomask according to claim 1 is used in a photo process for manufacturing a semiconductor device.

By this, in a photomask having a pellicle,
If it is necessary to remove the pellicle frame from the photomask for some reason, the pellicle frame can be attached and detached from the photomask by the relatively easy method of removing the fixing jig. Since no adhesive is used to fix the pellicle frame, there will be no adhesive left on the photomask when the pellicle frame is removed. A photomask can be used for this purpose, and has the effect of significantly improving mass productivity in the manufacture of semiconductor devices.

[Brief explanation of drawings]

FIG. 1-A is a diagram showing a photomask, a pellicle frame, and a fixing jig according to an embodiment of the present invention. FIG. 1-B is a diagram in which a pellicle frame is attached to a photomask in an embodiment of the present invention. FIG. 1-0 is a diagram in which a pellicle frame is attached to a photomask in an embodiment of the present invention. FIG. 2-A is a diagram showing a pellicle frame used in an embodiment of the present invention. FIG. 2-B is a diagram showing a pellicle frame used in an embodiment of the present invention. FIG. 3-A is a diagram showing a fixing jig used in an embodiment of the present invention. FIG. 3-B is a diagram showing a fixing jig in an applied example of the embodiment of the present invention. FIG. 4 is a diagram showing an example of application of the embodiment of the present invention. FIG. 5 is a diagram illustrating a conventional photomask with a pellicle. 11... Fixing jig 12... Pellicle frame 13... Photomask 21... Pellicle frame 22... Pellicle 31... Thin film rubber 32 ・ 33 ・ 41 ・ 42 ・ 43 ・ 51 ・ 52・ 53 ・ ・Fixing jig, U-shaped fixing jig, fixing jig, pellicle frame, photomask, photomask, pellicle frame, pellicle Applicant Seiko Epson Corporation Agent Patent attorney Kizobe Suzuki (and 1 others) Figure 1-B Figure 2-A Figure 2-B ＼ Figure 3-8 Figure 3-B Figure 4

Claims (1)

[Claims] 1) In a photomask equipped with a pellicle, an adhesive layer is not provided between the photomask and a pellicle frame for mounting and fixing at a certain distance from the pellicle, and the pellicle frame and A photomask, characterized in that it is held together with the photomask and is fixed using a removable jig. 2) The photomask according to claim 1, wherein at least a portion of the pellicle frame is provided with a holding margin for simultaneously holding and fixing the pellicle frame and the photomask using a jig. 3) The photomask according to claim 1, wherein the jig for simultaneously holding and fixing the pellicle frame and the photomask has a structure that uses its own elastic force to hold the pellicle frame and the photomask. 4) The photomask according to claim 1, wherein a non-slip surface of the fixing jig that contacts the pellicle frame and the photomask is provided. 5) The photomask according to claim 1, wherein a cushioning material is provided on the surface of the pellicle frame that is in contact with the photomask. 6) A method for manufacturing a semiconductor device, comprising using the photomask according to claim 1 in a photo process for manufacturing a semiconductor device.